Method for evaluating the halves of slaughtered animals by optical image processing

ABSTRACT

The invention relates to a method for evaluating the halves of slaughtered animals by optical image processing. A simple computerized method for sufficiently reliable evaluation is obtained even when the symmetry plane has been missed during cutting of the slaughtered animals due to cutting error by detecting two salient points and a straight line ( 5 ) in a photogrammetric reliable manner and by additionally calculating a parallel line ( 6 ) and a vertical line ( 7 ), wherein the end of the connecting bone ( 2 ) on the body side is used as first salient point and the central extension of the back fat ( 4 ) is used as a first direction.

FIELD OF THE INVENTION

The invention defines a method for evaluating half carcasses, also knownas sides, of slaughtered animals that are detected at the productentrance, classification points, or product exit in slaughterhouses andmeat packing facilities, by optical image processing. As a rule, insidethe slaughterhouses and meat packing facilities, these half carcassesare transported, hanging from a hook, by means of special transportsystems. The evaluation presented here is designed in particular forsides of pork, but it is also suitable in principle for sides of cattle,sheep, goats, or other large and small slaughtered animals.

BACKGROUND OF THE INVENTION

In general, the sides of pork are registered, weighed and evaluated. Thesides of pork are evaluated commercially by an appropriate officialmarket classification. The thickness of the fat and of the flesh isdetected at legally prescribed points specific to particular countriesor states. For sorting purposes, a market value determination of thecarcasses is made, as a rule; the finding is more conclusive if manyfurther specific parameters are included, but usually these are notstandardized.

German Patents DE 41 09 345 C2 and DE 44 08 604 C2 disclose an analysisor evaluation of carcass halves by means of image processing. In thisprocessing, a photogrammetrical assessment of partial images of thecarcass halves is done, beginning at the rumpbone. A disadvantage ofsuch methods is that the rumpbone, as a prominent point in the pictureof the carcass halves, is not adequately reliably selectable under theusual conditions in slaughterhouses, since because of mistakes insplitting the carcass that sometimes occur (if the division is notprecisely in the plane of symmetry of the carcass), portions of thespinal column are missing from one half of the carcass or are coveredwith leaf fat, also known as pork flare, yet the spine is known to belocated in only a narrow region of the plane of symmetry of the body ofthe animal. Another disadvantage is that selecting the spinal column iscomplicated and requires much computation by way of object analysis withpredefined contour and object parameters.

SUMMARY OF THE INVENTION

The object of the invention is to develop a method that assuresevaluation of carcass halves by image processing while overcoming theabove disadvantages; in particular with a method that is simple toachieve in terms of computation, adequately reliable evaluation isintended to be accomplished, even if splitting errors mean that theplane of symmetry is missed when the carcasses are split.

This object is attained with the characteristics recited in claim 1.Further features of the invention will become apparent from thedependent claims.

The object is attained essentially in that for the photogrammetricalevaluation and assessment, only those body components that extendanatomically over a wide region relative to the plane of symmetry of thecarcass and are reliably detectable visually are used; the hipbone, thegluteus medius muscle (MGM), in particular, and the back fat meet theserequirements.

Because there are two hipbones, which meet solely in the plane ofsymmetry (inside the hip joint), the cut always runs through a hipboneand is thus optically visible and can be reliably evaluated bycomputation. Because it cannot be overlapped by leaf fat, the splitsurface cannot be visually concealed. The MGM and the back fat extend inthe same over broad portions of the width of the back and are alwaysreliably selectable visually and by computation by way of thetransitions in brightness or color.

One advantageous exemplary embodiment of the invention is explained infurther detail in conjunction with FIG. 1 in the form ofphotogrammetrical evaluation.

BRIEF DESCRIPTION OF THE DRAWING

In FIG. 1, an image region 1 furnished for photogrammetrical evaluationincludes an optical picture of the loin and leg region of the carcasshalf, including the end of the hipbone 2 nearer the body, the end of theMGM 3 nearer the body, and the outer boundary of the back fat 4. Theoval-rounded hipbone (bright in front of a red peripheral region), whichis readily visible and selectable by computation because of thetransitions in brightness or color, is detected, and advantageously theend of the hipbone 2 nearer the body is made available, as a firstprominent point, to the photogrammetrical evaluation. The back fat isalso detected with respect to its boundaries on the basis of thebrightness or color transitions (bright in front of a red peripheralregion or background) and made available to the photogrammetricalevaluation in the form of a first straight line 5, in terms of its meancourse. It is conceivable at the same time to detect its boundaries andthe surface area or the width to be determined or detected, and to makea point of minimal fat thickness available as a second prominent pointto the photogrammetrical evaluation. However, it is advantageous todetect the MGM 3 on the basis of the brightness or color transitions(red in front of a bright peripheral region) and to furnish the end ofthe MGM 3 nearer the body to the photogrammetrical evaluation as asecond prominent point. Given a known side of the carcass half, thestraight line 5 can be represented by computation as a parallel 6through the first prominent point—in the form of the end of the hipbone2 nearer the body—whereupon a vertical 7 through the second point isunequivocally determined; this vertical is advantageously calculatedwith respect to its segments as far as the parallel 6 and the outerboundary of the back fat 4. An advantageous refinement provides thecalculation of the length from the first prominent point—in the form ofthe end of the hipbone 2 nearer the body—to the base point of thevertical 7; further base points 8 derived from this length can also becalculated—such as a point which divides this line in a ratio of 2:1 andby which further verticals 9 are determined—and their segments areadvantageously calculated analogously. The calculated lengths of thesegments or area values between them serve as specific parameters forevaluating the carcass half. It is especially advantageous, by way ofthis computationally reliable selection of two points and one direction,to simulate the classical two-point method in modified formphotogrammetrically.

Reference numerals used

1 Image region

2 End of a hipbone nearer the body

3 End of the MGM nearer the body

4 Back fat

5 Straight line

6 Parallel

7 Vertical

8 Further base points

9 Further vertical

What is claimed is:
 1. A method for evaluating carcass halves by opticalimage processing, in which an image region (1) furnished forphotogrammetrical evaluation contains an optical picture taken of theloin and leg region of the carcass half, and readily visible bodycomponents are detected by computation and specific parameters for theevaluation are ascertained, characterized in that two prominent pointsand one straight line (5) are reliably detected photogrammetrically,with the end of an hipbone (2) nearer the body is used as a firstprominent point, and the mean course of the back fat (4) is used as thestraight line (5); that a parallel (6) through the first prominent pointand a vertical (7) through the second prominent point relative to thestraight line (5) are calculated; and that the length of the segments ofthe vertical (7) to the parallel (6) and to the outer boundary of theback fat (4) are used as specific parameters for the evaluation.
 2. Themethod for evaluating carcass halves by optical image processing ofclaim 1, characterized in that as the second prominent point, the pointof minimal fat thickness of the back fat (4) or the end of the MGM (3)nearer the body is reliably detected photogrammetrically.
 3. The methodfor evaluating carcass halves by optical image processing of claim 1characterized in that the length of the distance on the parallel (6)from the first prominent point to the base point of the vertical (7) iscalculated.
 4. The method for evaluating carcass halves by optical imageprocessing of claim 3, characterized in that from the calculated lengthof the distance, further base points (7) on the parallel (6) and furtherverticals (8) are calculated.
 5. The method for evaluating carcasshalves by optical image processing of claim 1, characterized in that atwo-point method modified for reliable photogrammetrical detection isrealized.